The possible transmission routes of hepatitis C virus (HCV) in
patients without overt parenteral exposure (sporadic or community
acquired form) were examined. Saliva and urine specimens obtained
from type C hepatitis patients, whose sera were positive for the
HCV genome, were examined by reverse transcription and polymerase
chain reaction (RT-PCR). By analyzing the factors that influenced
the detection of the HCV genome by PCR, we developed a single round
method which enabled semiquantitative detection with higher
sensitivity than that obtained with nested PCR. Single round PCR
revealed that 34.8% (8 of 23) of saliva and 56.5% (13 of 23) of
urine specimens from patients with type C hepatitis contained the
HCV genome. The amounts of HCV genome in saliva and urine specimens
correlated with those in serum. The relative amounts of HCV genome
in serum, saliva, and urine from a chronic type C hepatitis patient
were determined by comparing the reciprocal of the smallest volume
of the specimens in which the PCR products were visualized in
agarose gels (PCR units/ml), and the values were 1 x 10(5), 5 x
10(1), and 3 x 10(1) PCR units/ml for serum, saliva, and urine
specimens, respectively.